Engineering Commons^™

Design Of A Temperature Sensor For Gallium Arsenide Ic Applications, Raviprakash Raviprakash Gutala

Theses

This thesis presents the design of a temperature sensor circuit including sensor, differential amplifier, and a memory element for gallium arsenide IC standard cell applications. A standard 1-um depletion-mode GaAs MESFET technology has been used for the design of the circuit. The circuit is intended to be used as a standard cell in GaAs les providing an alarm when the sensor temperature reaches 125 °C. The circuit includes a NAND latch which is set when the chip cell temperature reaches 125 °C. The output of the latch can be sensed by additional circuits (on or off the GaAs chip) which …

Reliability Problems And Failure Mechanisms In Ic Packaging, Dilip J. Patel

Theses

Today, reliability is acknowledged as an important item in design and operation of electronics circuits and system.

This thesis provides information on evaluation of the reliability for hermetic and non hermetic IC packages made by different manufacturers.

Literature study concentrates on the reliability and related problems in IC packages developed between 1970 and 1988.

Several failure mechanisms and failure modes are discussed to point out how higher reliability in IC packages may be achieved.

The bibliography is given in a chronological order to help further research in this area.

Generation Of Atomic Nitrogen By Gas Discharge In Microwave Cavity, Jong-Shun Shieh

Theses

A microwave discharge system for producing atomic nitrogen at low flow rate and low pressure has been investigated. The molecular nitrogen passes through a microwave cavity in a quartz tube and is dissociated by the microwave energy. Subsequent recombination of nitrogen atoms produces a characteristic yellow glow due to the relaxation of excited molecular nitrogen to its ground state. The titration of nitric oxide with atomic nitrogen was used to measure the atomic nitrogen yield. At a 2 sccm nitrogen flow rate the atomic nitrogen yield was 8.75*10¹⁵ atom/sec, which corresponds to a nitrogen generation efficiency of about 1%. …

A Cmos Digital Temperature Sensor For Asic Vlsi Standard Cell Design, Chih-Ta Sung

Theses

This thesis describes the design of a CMOS digital temperature sensor cell including the physical layout database.This cell is designed for implementation within an ASIC VLSI chip as a standard cell . The digital temperature sensor can trigger an alarm signal and turn off power for preventing fatal damage in the VLSI chip if overheating occurs.A digital output also permits measurement of temperature over the 0 - 120°C range with ±3.4°C accuracy using standard VLSI foundry processing. Two sensing elements are implemented in a differential mode within the temperature sensor cell. An operational amplifier is used in the successive approximation …

Use Of The Lms Algorithm In Ecg Analysis, Xiaohua Yang

Theses

The purpose of this thesis is to develop an IBM PC-AT based system to effectively process electrocardiogram (ECG) signals. Adaptive filter theory is used to implement a noise cancellation system (adaptive noise canceller), which adaptively cancels the ECG signals resulting in real ECG noise. The adaptive process is based on the well known least-mean square (LMS) algorithm.

The noise canceling system is software based. Several programs have been written, which include analog to digital converter control, data acquisition and storage, data retrieval, adaptive filtering and digitized data graphics.

The thesis presents numerous computer experiments. The performance of the adaptive noise …

Progressive Transmission Of Images Using Pyramidal Structure, Chin-Hua Hsu

Theses

A progressive image transmission scheme based upon Laplacian pyramid structure is used for image coding over low-bandwidth channels. The filtering and differential pulse code modulation (DPCM) methods of image coding are generalized to allow quantization of the Laplacian images. Filtering is performed with a local, symmetric weighting function. The three different quantizers, (1) scalar quantizer, (2) memoryless vector quantizer (VQ), and (3) finite state vector quantizer (FSVQ), are used here to compare the results. In the receiver end, the image can be reconstructed using reverse procedure. The reconstructed image is not the same as the original image because of the …

A Wideband Continuous Phase Shifter For Ka-Band, William J. Tanis

Theses

The design, fabrication and test of a 45 degree microstrip phase shifter capable of full Ka-band performance is presented. The design uses a Lange coupler with two ports terminated with beam-lead varactor diodes to provide continuous phase shift. Although this concept has been employed at X-band and below, this thesis demonstrates its feasibility for wideband use at frequencies as high as 40 GHz. The design uses thin-film capacitors, beam-lead diodes, simulated grounds, and air bridges to achieve a planar geometry and to simplify the production process. Detailed test results using various test circuits are shown for comparison to actual phase …

Design Of A Lan Based Data Acquisition System For Sensor Applications, Krishna Murthy Uppunda

Theses

This thesis presents the design of a local area network (LAN) based data acquisition system for sensor applications. The circuit designed forms the robotic LAN (RLAN) interface between the sensor IC nodes and the ARCNET network. The RLAN network uses two packet protocols. The sensor data request (SDR) packet is received by the sensor IC nodes and the sensor transmits the sensor data (SD) packet. The RLAN interface provides a two way communication between the sensors and the ARCNET network. Whenever an ARCNET node receives the SDR packet, it stores the packet temporarily in a 1k RAM buffer. The RLAN …

Theoretical Model For The Images Formed By A Spherical Particle In A Coherent Imaging System: Comparison, Scott Alan Schaub, D. R. Alexander, J. P. Barton

Department of Electrical and Computer Engineering: Faculty Publications

A simple theoretical model is presented that allows calculation of the image produced by a spherical absorbing particle illuminated by monochromatic, coherent laser light. Results presented in this paper are restricted to a singe-lens imaging system, although generalization to more complex imaging system configurations would be straightfoward. The method uses classic Lorenz-Mie scattering theory to obtain the electromagnetic field external to an absorbing spherical particle and a Fourier optics approach to calculate the intensities in the image plane. Experimental results evaluating focus characteristics are examined for 50 um diameter water droplets using an N2 laser imaging system in conjunction with …

Assessment Of Squirrel-Caused Power Outages, J. Chris Hamilton, Ron J. Johnson, Ronald M. Case, Michael W. Riley

School of Natural Resources: Faculty Publications

Squirrel-caused power outages in Lincoln and Omaha, Nebraska, were evaluated by examining company power outage reports and by consulting with power company representatives. Reports showed that squirrel-caused outages at pole-mounted transformers were most prevalent during May, June, and October (48% of total) and between 1 and 4 h after sunrise (38%), patterns that coincide with squirrel dispersal or morning activity periods. In Lincoln, 1980 and 1981, squirrels caused 177 outages per year, which was 24% of all outages and 90% of animal-caused outages. Estimated minimum annual costs were $23 364 for repairs, public relations, and lost revenue while meters were …

Feasibility Study Of Maine's Small Hydropower Potential, James D. Sysko

Maine Collection

Feasibility Study of Maine's Small Hydropower Potential

Prepared by James D. Sysko, Small Hydro East, for the Maine State Planning Office, Maine Office of Energy Resources, January 1989.

"This study focuses on finding potential hydropower sites of approximately 50 kw to 1000 kw in capacity."

Symmetric Self-Electro-Optic Effect Device: Optical Set-Reset Latch, Differential Logic Gate, And Differential Modulator/Detector, Anthony L. Lentine, Harvard S. Hinton, David A. B. Miller, Jill E. Henry, J. E. Cunningham, Leo M. F. Chirovsky

Electrical and Computer Engineering Faculty Publications

The symmetric self-electrooptic-effect device (S-SEED), a structure consisting of two p-i-n diodes electrically connected in series and acting as an optically bistable set-reset latch, is discussed. Applications and extensions of this device are also discussed. The devices do not require the critical biasing that is common to most optically bistable devices and thus is more useful for system applications. They have been optically cascaded in a photonic ring counter and have been used to perform different NOR, OR, NAND, and AND logic functions. Using the same device, a differential modulator that generates a set of complementary output beams with a …

Generalized Model For The Optical Absorption Edge In A-Si:H, T. Datta, John A. Woollam

Department of Electrical and Computer Engineering: Faculty Publications

We have reanalyzed the published optical absorption coefficient data for a-Si:H and introduced a divergence temperature, a new concept in the physics of these materials.

Algorithms For Multi-Channel Dtmf Detection For The We Dsp32 Family, Steven L. Grant, J. Hartung, G. L. Smith

Electrical and Computer Engineering Faculty Research & Creative Works

The authors describe two DTMF (dual-tone multiple frequency) detection algorithms that are highly efficient in the use of both real time and memory. The first algorithm is based on linear prediction (LP) and can be used to implement up to 32 DTMF detectors on a single 25-MHz NMOS WE DSP32. Using a 50-MHZ WE CMOS DSP32C, up to 45 detectors can be implemented. The second algorithm is based on a slight modification of the Goertzel algorithm and can be used to implement up to 16 DTMF detectors on a single DSP32 and up to 32 detectors on a DSP32C. In …

Central-Station Photovoltaic Plant With Energy Storage For Utility Peak Load Leveling, Badrul H. Chowdhury

Electrical and Computer Engineering Faculty Research & Creative Works

The impact of photovoltaic (PV) power generation with energy storage on the electric utility's load shape for load leveling purposes is explored. Results show that utilities employing battery storage for peak load shaving might benefit from use of photovoltaic power, the extent of its usefulness being dependent on the specific load shapes as well as the photovoltaic array orientations. Typical utility load shapes both in the eastern and in the western parts of the US are examined for this purpose. Although photovoltaic power generation seems to have a bigger impact on the load of the western utility, utilities in both …

Modeling The Electromagnetic Radiation From Electrically Small Table-Top Products, Todd H. Hubing, J. Frank Kaufman

Electrical and Computer Engineering Faculty Research & Creative Works

It is noted that the most difficult radiated electromagnetic interference (EMI) problems with table-top products often occur at frequencies where the maximum dimensions of the product are much smaller than a wavelength. Electrically small table-top products tend to be much more efficient radiation sources than dipole source models would predict, and the radiation is generally much more difficult to contain than other types of EMI source models indicated. The ways in which electrically small sources radiate are investigated, and a technique for modeling electrically small table-top products that have power or signal cables is proposed. The end-driven wire model is …

The Effect Of Cable Terminations On Emi Measurements, Todd H. Hubing

Electrical and Computer Engineering Faculty Research & Creative Works

The effects of using uncontrolled or undefined cable terminations during electromagnetic interference (EMI) measurements was investigated. Several different models are described along with corresponding measurements in order to illustrate how specific terminations can be used to achieve particular measurement goals. It is noted that until a well-defined method of terminating power and signal cables is introduced, the best the EMI test engineer can do is to be aware of the significance of common-mode terminations and try to avoid situations where the common-mode termination impedance is completely undefined or not repeatable.

Lqg/Ltr Controller Design Using A Reduced Order Model, Rajiva Prakash, Vittal S. Rao

Electrical and Computer Engineering Faculty Research & Creative Works

A specific robust controller design procedure, linear quadratic Gaussian with loop transfer recovery (LQG/LTR), is studied. LQG/LTR design using a reduced-order model is performed. The error due to the use of the reduced model is accounted for by computing multiplicative error. All closed right half plane modes of the given system are included in the reduced-order model. The reduced-order LQG/LTR controller design procedure is applied to the problem of lateral attitude control of a drone aircraft. The case study demonstrates the reduction/design steps for a practical problem.

The Effects Of Bandwidth Limiting Tuning Elements On A Synchronously Pumped Mode-Locked Dye Laser, Bahram Zandi

Dissertations and Theses

In this study an improved description of the bandwidth limiting tuning filters has been introduced into a semiclassical model for a synchronously pumped mode-locked dye laser system. This model is an improvement over the traditional rate equation approach since it has detailed representations of the energy levels, rotational distribution, and coherence effects. The new set of equations has been solved numerically using the best available values for the various parameters, and autocorrelations have been computed for a range of different length detuning and bandwidth limiting elements. In the experiments, an acousto-optically mode-locked argon ion laser is used to synchronously pump …

Automatic Color Segmentation Of Images With Application To Detection Of Variegated Coloring In Skin Tumors, Scott E. Umbaugh, Randy Hays Moss, William V. Stoecker

Electrical and Computer Engineering Faculty Research & Creative Works

A description is given of a computer vision system, developed to serve as the front-end of a medical expert system, that automates visual feature identification for skin tumor evaluation. The general approach is to create different software modules that detect the presence or absence of critical features. Image analysis with artificial intelligence (AI) techniques, such as the use of heuristics incorporated into image processing algorithms, is the primary approach. On a broad scale, this research addressed the problem of segmentation of a digital image based on color information. The algorithm that was developed to segment the image strictly on the …

Gaas Photoconductive Closing Switches With High Dark Resistance And Microsecond Conductivity Decay, M. S. Mazzola, K. H. Schoenbach, V. K. Lakdawala, R. Germer, G. M. Loubriel, F. J. Zutavern

Electrical & Computer Engineering Faculty Publications

Silicon-doped n-type gallium arsenide crystals, compensated with diffused copper, were studied with respect to their application as photoconductive, high-power closing switches. The attractive features of GaAs:Cu switches are their high dark resistivity, their efficient activation with Nd:YAG laser radiation, and their microsecond conductivity decay time constant. In the authors' experiment, electric fields are high as 19 kV/cm were switched, and current densities of up to 10 kA/cm² were conducted through a closely compensated crystal. At field strengths greater than approximately 10 kV/cm, a voltage `lock-on' effect was observed.

Integrated Circuits Interconnect Metallization For The Submicron Age, Kamesh V. Gadepally, Roger M. Hawk

Journal of the Arkansas Academy of Science

The interconnect metallization being used by the semiconductor industry has been aluminum or aluminum silicon. Aluminum silicon is being replaced by aluminum copper and aluminum copper silicon, due to its superior resistance to electromigration and hillock growth. This paper discusses the implementation of aluminum copper/silicon alloys in semiconductor processing, along with a review of the problems and advantages of the same.

Versatile Potentiostat With Optional Computer Control, Gary L. Fuller, William A. Russell Jr., Roger M. Hawk, James D. Wilson, P. D. Bratton

Journal of the Arkansas Academy of Science

A versatile potentiostat which can supply a maximum of 125 ma is described. The potentiostat uses readily available electronic components and an interface is detailed which allows the potentiostat optional computer control.

Computer-Controlled Programmable Pulse Generator For A Jeol Jnm-Ft-1a Radio Frequency Amplifier Section Of A Nuclear Magnetic Resonance Spectrometer, William H. Russell, Roger M. Hawk

Journal of the Arkansas Academy of Science

A microprocessor controlled programmable pulse generator was specifically designed to interface with the JEOL JNM-FT-1 A Radio Frequency (RF) section of a nuclear magnetic resonance (NMR) spectrometer. The programmable pulse generator was programmed and controlled by an IBM compatible computer. Statis rams were utilized as the programmable pulse generator's on board memory which were used to store the pulse sequences. Pulse widths can be programmed from 0.2 microseconds to 14.3 minutes. The JEOL RF section is unique in that it allows the pulse generator to control the phase of the RF transmitted to the NMR probe and whether the sample …

Image Processing Instrumentation For Giardia Lamblia Detection, Cy R. Tamanaha, Mark A. Gross

Journal of the Arkansas Academy of Science

Currently, the identification and enumeration of Giardia Iamblia cysts are based upon microscopic methods requiring individuals proficient in this area. It is a tedious process which consumes time that could be constructively used elsewhere. This project attempts to alleviate that burden by employing a computer to automatically process Indirect Fluorescent Antibody (IFA) prepared slides using digital image processing techniques. A computer controlled frame grabber, in conjunction with a CCD TV camera mounted on the epi-fluorescence microscope phototube, captures the light intensities of the objects in view under the microscope objective. The captured image is stored as pixels, with each pixel …

Expansion Of An Existing Power System - A Study, Suresh Arunachalam

Masters Theses

"An existing paper mill is being expanded to increase its installed capacity. Concurrent expansions will be increasing the electrical demand by 40 - 50 MVA. The expansion also includes the addition of DC drives. The existing system has to be used effectively while additional equipment may be added to cater the load increase. Load flow study with various single line diagram configurations has been carried out to find the required solution. A harmonic analysis was also carried out on the suggested new system to install the required filters and capacitor blanks"--Abstract, page ii.

The Multiprocessor System With A Fairly Weighted Global Bus Arbitration Circuit, Shinobu Doi

Theses and Dissertations

The objective of this thesis is to investigate various multiprocessor system structures and to implement and test the resultant system configuration that offers high reliability and availability, ease of expansion, ease of programming, and increased computing performances. The resultant system is a MC68000 based tightly coupled multiprocessor system with large local memories and local I/Os, arbitrated by a specially designed arbitration circuit to implement pseudo random global bus granting. Each of the computer modules is an enhanced independent uniprocessor system with channel access switches to access the global memory. In its multiprocessor mode one computer module cooperates with the other …

Consequences Of Valley Filtering On Abrupt Junction Algaas/Gaas Heterojunction Bipolar Transistors, Amitava Das, Mark S. Lundstrom

Department of Electrical and Computer Engineering Faculty Publications

Electron transport in AlGaAs/GaAs heterojunction bipolar transistors with compositionally abrupt emitter‐base junctions is examined. Transport across the abrupt emitter‐base heterojunction is treated quantum mechanically, and the Monte Carlo technique is used to study transport through the base. Although there is a sizeable population of upper‐valley electrons in the bulk emitter, the AlGaAs/GaAs heterojunction is found to favor the injection of Γ‐valley electrons into the base. This valley filtering effect enhances device performance by reducing base transit time, but quantum mechanical tunneling lowers the average energy of the injected flux which increases base transit time. The design of a heterojunction bipolar …

Effective Minority‐Carrier Hole Confinement Of Si‐Doped, N+‐N Gaas Homojunction Barriers, H. L. Chuang, M. E. Klausmeier-Brown, Michael R. Melloch, Mark S. Lundstrom

Department of Electrical and Computer Engineering Faculty Publications

he electrical performance of Si‐doped n+‐n GaAs homojunction barriers grown by molecular‐beam epitaxy (MBE) is characterized and analyzed. We employed a successive etch technique to study hole injection currents in GaAs n+‐n‐p+ solar cells. The results of the analysis show that minority‐carrier holes in our MBE‐grown material have a mobility of 293 cm2/V s for an n‐type Si‐doping level of 1.5×1016 cm−3 at 300 K. The interface recombination velocity for these homojunction barriers is estimated to be less than 1×103 cm/s, and it appears to be comparable to that recently observed for …

Design Of The Electronics And Optics Needed To Support Charge-Coupled Devices : A Project Report ..., Kah Yep Zee

University of the Pacific Theses and Dissertations

Over the last five years, charge-coupled devices (CCD) have been improved dramatically in terms of sensitivity, manufacturability and particularly, cost. This has enabled them to be used economically in many more industrial and commercial electronic imaging processes. They are found in products ranging from video cameras to satellite-based camera systems. This has sparked my interests in these devices, and with a great deal of encouragement from Dr. Turpin, I decided to base my Master's thesis/project on a CCD. The project was mainly based on the design of the electronics and optics needed to support a CCD. The particular circuit design …